The common method of wrapping stacked packages on pallets, such as with stretch plastic film or netting, is by moving the pallet and its load of packages with a fork lift truck to a stationary wrapping machine. The wrapping machine then wraps the load of packages and the wrapped load and pallet is removed from the stationary wrapping machine by a fork lift truck in order to make room for the next loaded pallet to be brought to the wrapping machine. This method is relatively slow, and is quite labor-intensive because many fork lift trucks and truck operators are required in order to supply and remove loaded pallets to and from the wrapping machine in a timely manner in order for the wrapping machine to be operated in any way approaching an efficient manner.
An alternative approach is suggested in U.S. Pat. No. 5,140,795, which is hereby incorporated by reference, in which a wrapping machine is suspended from an overhead beam, and the machine is controlled by hard-wire controls and sliding electrical contacts along the beam so as to move along the elevated beam to multiple wrapping stations as determined by an operator. While this approach is an improvement, the suspension system requires substantial structural requirements, and the sliding contacts may give false signals, and the beam may interfere with other structures such as the overhead conveyors used in some installations.